JPWO2019008722A1 - Stator, electric motor, driving device, compressor, air conditioner, and stator manufacturing method - Google Patents

Abstract

The stator includes a stator core. The stator core includes a yoke portion extending in the circumferential direction around the axis, a plurality of teeth extending in a direction from the yoke portion toward the axis or in a direction away from the axis, and a circumferential direction of the plurality of teeth. And a slot formed between two adjacent teeth. In the stator core, a plurality of laminated elements are laminated in the axial direction, and a gap is formed between two laminated elements adjacent to each other in the axial direction among the laminated elements. The stator also includes a first insulating portion provided in the slot, and a second insulating portion provided between the stator core and the first insulating portion and closing the slot side of the gap.

Description

  The present invention relates to a stator, an electric motor, a drive device, a compressor, an air conditioner, and a stator manufacturing method.

  The stator of the electric motor has a stator core and a winding wound around the stator core. The stator core is composed of a laminated body in which electromagnetic steel plates are laminated, and the winding is disposed in a slot formed in the stator core.

  Further, for example, Patent Document 1 discloses a stator in which an insulating film made of a polyester film is disposed between a stator core and a winding.

JP 2000-333398 A (see FIG. 1)

  Here, in the manufacturing process of the stator core, a gap is generated between the laminated magnetic steel sheets. For this reason, when the electric motor is used in a compressor or the like, the lubricating oil and the refrigerant may enter the gap between the electromagnetic steel sheets, thereby increasing the leakage current and reducing the electric motor efficiency.

  Moreover, the uneven | corrugated | grooved part which arose in the punching process of an electromagnetic steel plate exists in the surface by the side of the slot of a stator core. Therefore, even if an insulating film is arranged between the stator core and the winding as in Patent Document 1, the lubricating oil and the refrigerant are introduced into the gap between the magnetic steel sheets from the gap between the insulating film and the uneven portion of the stator core. There is a possibility of intrusion.

  The present invention has been made to solve the above-described problems, and has an object to reduce leakage current and improve motor efficiency.

  The stator according to the present invention includes a yoke portion extending in the circumferential direction around the axis, a plurality of teeth extending in a direction from the yoke portion toward the axis or in a direction away from the axis, and a circumference of the plurality of teeth. A stator core having a slot formed between two teeth adjacent to each other in a direction, wherein a plurality of laminated elements are laminated in the direction of the axis, and two of the laminated elements adjacent to each other in the axis direction A stator core having a gap between the laminated elements, a first insulating part provided in the slot, and a second part provided between the stator core and the first insulating part to close the slot side of the gap. And an insulating part.

  According to this invention, since the slot side of the gap of the laminated element of the stator core is closed by the second insulating portion, the lubricating oil and refrigerant flowing in the slot are less likely to enter the gap of the laminated element. Thereby, leakage current can be reduced and motor efficiency can be improved.

1 is a cross-sectional view showing an electric motor in a first embodiment. 1 is a longitudinal sectional view showing an electric motor according to Embodiment 1. FIG. FIG. 3 is a diagram showing a stator core of the electric motor in the first embodiment. 3 is an enlarged view showing a stator core of the electric motor according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view showing a stator core, a first insulating portion, and a second insulating portion in the first embodiment. FIG. 3 is an enlarged cross-sectional view showing a part of the stator in the first embodiment. FIG. 3 is a perspective view showing an external shape of a first insulating portion in the first embodiment. It is a schematic diagram for demonstrating the punching process of an electromagnetic steel plate. It is the side view (A) and front view (B) for demonstrating the uneven | corrugated | grooved part which arises at the punching process of an electromagnetic steel plate. It is the schematic diagram (A) for demonstrating the formation process of the crimping of an electromagnetic steel plate, and the schematic diagram (B) and (C) which show the example of the shape of a crimping. It is sectional drawing which expands and shows the end surface of the stator core formed with the punching surface of an electromagnetic steel plate. 3 is an enlarged cross-sectional view of an outer peripheral surface of a stator core in the first embodiment. FIG. FIG. 3 is an enlarged cross-sectional view illustrating a slot-side surface, a first insulating portion, and a second insulating portion of the stator core in the first embodiment. 3 is a flowchart showing manufacturing steps of the stator in the first embodiment. It is a top view which shows the stator core punched out from the electromagnetic steel plate. FIG. 6 is a schematic diagram for explaining an example of a method for forming a first insulating portion in the first embodiment. FIG. 3 is a schematic diagram (A) and (B) illustrating an example of a winding method around the stator core in the first embodiment. FIG. 3 is a block diagram showing a control system of the electric motor in the first embodiment. FIG. 6 is a cross-sectional view showing a configuration example in which the second insulating portion enters the laminated gap of the stator core in the first embodiment. FIG. 9 is an enlarged cross-sectional view showing a slot-side surface, a first insulating portion, and a second insulating portion of a stator core in the second embodiment. FIG. 6 is a cross-sectional view showing an electric motor in a third embodiment. It is sectional drawing which shows the structure of the compressor which can apply the electric motor of each embodiment. It is a figure which shows the structure of the air conditioning apparatus provided with the compressor of FIG.

Embodiment 1 FIG.
<Configuration of motor>
The electric motor 100 according to the first embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing a configuration of electric motor 100 in the first embodiment. This electric motor 100 is a permanent magnet embedded type electric motor in which a permanent magnet 53 is embedded in the rotor 5, and is used, for example, in a compressor 500 (see FIG. 22) in which lubricating oil and refrigerant are enclosed.

  The electric motor 100 is an electric motor called an inner rotor type, and includes a stator 1 and a rotor 5 that is rotatably provided inside the stator 1. An air gap of, for example, 0.3 to 1.0 mm is formed between the stator 1 and the rotor 5.

  Hereinafter, the direction of the axis C1 which is the rotation axis of the rotor 5 is referred to as “axial direction”. Also. A circumferential direction around the axis C1 (indicated by an arrow R1 in FIG. 1 and the like) is referred to as a “circumferential direction”. The radial direction centered on the axis C1 is referred to as “radial direction”. FIG. 1 is a cross-sectional view of a plane orthogonal to the rotation axis (axis C1) of the rotor 5.

<Configuration of rotor>
The rotor 5 includes a cylindrical rotor core 50, a permanent magnet 53 attached to the rotor core 50, and a shaft 55 disposed at the center of the rotor core 50. The shaft 55 is, for example, the shaft of the compressor 500 (FIG. 22).

  FIG. 2 is a cross-sectional view (longitudinal cross-sectional view) of the electric motor 100 on a plane parallel to the axis C1. The rotor core 50 is formed by laminating a plurality of electromagnetic steel plates (lamination elements) in the axial direction and fastening both ends in the axial direction with fixing members 61 and 62. The thickness of the electromagnetic steel sheet constituting the rotor core 50 is, for example, 0.2 to 0.5 mm.

  Returning to FIG. 1, a plurality of magnet insertion holes 51 into which the permanent magnets 53 are inserted are formed along the outer peripheral surface of the rotor core 50. The magnet insertion hole 51 is a through hole that penetrates the rotor core 50 in the axial direction. The number of magnet insertion holes 51 is six here. However, the number of magnet insertion holes 51 is not limited to six, and may be two or more. There is a gap between the adjacent magnet insertion holes 51.

  The permanent magnet 53 is a flat plate-like member that is long in the axial direction, has a width in the circumferential direction of the rotor core 50, and has a thickness in the radial direction. The thickness of the permanent magnet 53 is 2 mm, for example. The permanent magnet 53 is composed of, for example, a rare earth magnet mainly composed of neodymium (Nd), iron (Fe), and boron (B). The permanent magnet 53 is magnetized in the thickness direction.

  Here, one permanent magnet 53 is arranged in one magnet insertion hole 51, but a plurality of permanent magnets 53 may be arranged in the circumferential direction in one magnet insertion hole 51. In this case, the plurality of permanent magnets 53 in the same magnet insertion hole 51 are magnetized such that the same poles are directed radially outward.

  Flux barriers (leakage magnetic flux suppression holes) 52 are formed at both ends in the circumferential direction of the magnet insertion hole 51. The flux barrier 52 suppresses leakage magnetic flux between adjacent permanent magnets 53. The core portion between the flux barrier 52 and the outer periphery of the rotor core 50 is a thin portion in order to suppress a short circuit of magnetic flux between the adjacent permanent magnets 53. The thickness of the thin portion is preferably the same as the thickness of the electromagnetic steel plate constituting the rotor core 50.

<Structure of stator>
The stator 1 includes a stator core 10, a first insulating part 2 and a second insulating part 3 provided on the stator core 10, and a winding 4 wound around the stator core 10. The stator core 10 includes an annular yoke portion 11 centering on the axis C1 and a plurality of teeth 12 extending radially inward from the yoke portion 11 (that is, in a direction toward the axis C1).

  The teeth 12 are arranged at regular intervals in the circumferential direction. Here, the number of teeth 12 is nine. However, the number of teeth 12 is not limited to 9, and may be two or more. Between the teeth 12 adjacent to each other in the circumferential direction, a slot 13 which is a space for accommodating the winding 4 is formed.

  The stator core 10 is incorporated inside the cylindrical frame 7 by shrink fitting, press fitting, welding, or the like. The frame 7 is a part of the sealed container 507 of the compressor 500 (FIG. 22), for example.

  Inside the frame 7, there are lubricating oil (for example, refrigeration oil) for preventing seizure of the compression element 501 (FIG. 22) of the compressor 500 and refrigerant that circulates in the refrigeration cycle. Lubricating oil and refrigerant mainly flow through the inside of the slot 13 and between the frame 7 and a notch 19 (described later). Here, although the case where both lubricating oil and a refrigerant | coolant flow is demonstrated, one should just flow among lubricating oil and a refrigerant | coolant.

  FIG. 3 is a plan view showing the stator core 10. The stator core 10 is configured by laminating electromagnetic steel sheets (lamination elements) having a thickness of 0.2 to 0.5 mm (more desirably 0.2 to 0.35 mm) in the axial direction. For example, a non-oriented electrical steel sheet is used as the electrical steel sheet, but the invention is not limited to this. Further, for example, an amorphous metal ribbon may be used instead of the electromagnetic steel sheet.

  The stator core 10 has a configuration in which a plurality of divided cores 10A are connected in the circumferential direction for each tooth 12. The number of divided cores 10A is the same as the number of teeth 12 (here, nine). Each of the divided iron cores 10A is connected to each other by a connecting portion 15 provided at an end portion of the yoke portion 11 on the outer peripheral surface 11a side.

  FIG. 4 is an enlarged view showing a part of the stator core 10. The yoke part 11 has the cyclic | annular outer peripheral surface 11a extended in the circumferential direction, and the inner peripheral surface 11b located in the radial direction inner side. The outer peripheral surface 11a is a surface fitted to the frame 7 (FIG. 1). The inner peripheral surface 11 b faces the slot 13.

  The yoke portion 11 has a split surface (end surface) 16 that defines both ends of the split iron core 10A in the circumferential direction. The dividing surface 16 extends radially outward from the inner peripheral surface 11b of the yoke portion 11, but does not reach the outer peripheral surface 11a. A hole 11 c is formed at the radially outer end of the dividing surface 16. The thin portion between the hole 11c and the outer peripheral surface 11a of the yoke portion 11 constitutes a connecting portion 15 that can be plastically deformed. In addition, the connection part 15 is not restricted to the plastically deformable thin part, For example, circular caulking (round caulking) may be sufficient.

  In a state where the stator core 10 is assembled in an annular shape, the split surfaces 16 of the split cores 10A adjacent to each other in the circumferential direction are in contact with each other. On the other hand, in a state where the stator core 10 is developed in a strip shape (see FIG. 15), the split surfaces 16 of the split cores 10A adjacent in the circumferential direction are separated from each other.

  A notch 19 is formed in the outer peripheral surface 11 a of the yoke portion 11. The notch 19 is a portion for chucking the stator 1 with a jig in a winding step (FIG. 17B) described later. Moreover, the area | region between the notch 19 and the flame | frame 7 becomes a flow path of lubricating oil and a refrigerant | coolant. As the lubricating oil and the refrigerant flow through the notches 19, the heat generated in the stator 1 is released.

  The teeth 12 extend radially inward from the central portion in the circumferential direction of the yoke portion 11 in the divided iron core 10A. The teeth 12 have a pair of side surfaces 12a that are both end surfaces in the circumferential direction, and a pair of end surfaces 12b (FIG. 2) that are both end surfaces in the axial direction. The winding 4 is wound around the side surface 12a and the end surface 12b. A side surface 12 a of the tooth 12 faces the slot 13.

  The tooth 12 has a tooth tip 120 at the radially inner end (ie, tip). Teeth tip 120 has an arcuate tip 12d that faces the outer peripheral surface of rotor 5 (FIG. 1). Teeth tip portion 120 has projecting portions 121 that project on both sides in the circumferential direction with respect to side surface 12a of tooth 12. A protruding surface 12c is formed on the radially outer side of the protruding portion 121 (that is, the side facing the yoke portion 11). The protruding surface 12 c faces the slot 13.

  A caulking portion (tea squeezing portion) 17 is formed in the central portion in the radial direction of the tooth 12. On both sides of the notch 19 in the yoke portion 11 in the circumferential direction, crimping portions (yoke crimping portions) 18 are respectively formed. The caulking part 17 of the tooth 12 and the caulking part 18 of the yoke part 11 fix a plurality of electromagnetic steel plates constituting the stator core 10 to each other.

  High dimensional accuracy and high rigidity of the stator core 10 can be obtained by fixing the plurality of electromagnetic steel plates to each other by the caulking portion 17 of the tooth 12 and the caulking portion 18 of the yoke portion 11. In addition, vibration and noise generated by the electromagnetic excitation force when the electric motor 100 is driven can be suppressed.

  Note that the crimping portion 17 is not limited to the central portion in the radial direction of the tooth 12, and may be formed at, for example, the central portion in the circumferential direction of the tooth tip portion 120 or the protruding portion 121. Further, the number of crimping portions may be the minimum number that can ensure the dimensional accuracy and rigidity of the stator core 10. For example, the crimping portions 17 of the teeth 12 may be omitted.

  FIG. 5 is a cross-sectional view showing a state in which the first insulating portion 2 and the second insulating portion 3 are provided on the stator core 10. FIG. 6 is a cross-sectional view showing a state where the winding 4 is wound around the stator core 10 via the first insulating portion 2 and the second insulating portion 3. FIG. 6 also shows the frame 7 and the rotor 5.

  As shown in FIG. 5, the first insulating portion 2 (also referred to as an insulator) covers the tooth peripheral portion 2 a that covers the side surface 12 a and the end surface 12 b (FIG. 2) of the tooth 12, and the inner peripheral surface 11 b of the yoke portion 11. It has the outer side wall part 2b and the inner side wall part 2c which covers the protrusion surface 12c of the protrusion part 121 of the teeth 12. FIG.

  Teeth peripheral portion 2a is a portion around which winding 4 is wound as shown in FIG. The outer wall portion 2b and the inner wall portion 2c are portions that guide the winding 4 wound around the tooth peripheral portion 2a from the radially outer side and the radially inner side. In addition, the inner wall part 2c also covers the circumferential end face of the protruding part 121 of the tooth 12.

  The material constituting the first insulating part 2 is preferably, for example, a powder resin, a liquid resin, a thermoplastic resin, an electrical insulating varnish, or an adhesive. More specifically, epoxy resin, liquid crystal polyester resin (added with fibrous inorganic reinforcing material or inorganic filler), polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polyethylene terephthalate, or ABS (acrylonitrile butadiene styrene) Resins are desirable. However, the constituent material of the 1st insulating part 2 is not limited to these.

  The first insulating portion 2 is formed by molding a resin integrally with the stator core 10 using a mold, or by assembling a resin molded body molded as a separate part to the stator core 10.

  The thickness of the first insulating portion 2 is preferably thicker from the viewpoint of ensuring insulation between the stator core 10 and the winding 4. However, if the thickness of the first insulating portion 2 is too thick, the cross-sectional area of the slot 13 becomes small, the amount of winding that can be accommodated in the slot 13 decreases, and the increase in copper loss (in inverse proportion to the winding amount) Electric motor efficiency decreases. In order to achieve both insulation performance and electric motor efficiency, it is desirable that the thickness of the first insulating portion 2 be in the range of 0.1 mm to 0.7 mm.

  A second insulating portion 3 (also referred to as a closing portion) is formed between the stator core 10 and the first insulating portion 2. The second insulating portion 3 is formed so as to cover the side surface 12a and the protruding surface 12c of the tooth 12 and the inner peripheral surface 11b of the yoke portion 11 (that is, the surface on the slot 13 side of the stator core 10).

  That is, the second insulating portion 3 includes a tooth side surface portion 3 a that covers the side surface 12 a of the tooth 12, a yoke inner surface portion 3 b that covers the inner peripheral surface 11 b of the yoke portion 11, and a tooth protruding surface portion that covers the protruding surface 12 c of the tooth 12. 3c.

  The tooth side surface portion 3 a is provided between the side surface 12 a of the tooth 12 and the tooth peripheral portion 2 a of the first insulating portion 2. The yoke inner surface portion 3 b is provided between the inner peripheral surface 11 b of the yoke portion 11 and the outer wall portion 2 b of the first insulating portion 2. The teeth projecting surface portion 3 c is provided between the projecting surface 12 c of the tooth 12 and the inner wall portion 2 c of the first insulating portion 2.

  The second insulating portion 3 is provided in order to prevent the lubricating oil and refrigerant flowing in the slot 13 from entering the gap between the electromagnetic steel plates of the stator core 10. Therefore, the second insulating portion 3 covers the surface on the slot 13 side of the stator core 10 (that is, the side surface 12a and the protruding surface 12c of the tooth 12, and the inner peripheral surface 11b of the yoke portion 11), and covers the surface. The recess 104 (described later) is formed to be closed.

  The second insulating portion 3 is made of a material having a relative dielectric constant smaller than at least one (preferably both) of lubricating oil and refrigerant. The material constituting the second insulating part 3 is preferably, for example, a powder resin, a liquid resin, a thermoplastic resin, an electrical insulating varnish, or an adhesive. More specifically, an epoxy resin, a liquid crystal polyester resin (added with a fibrous inorganic reinforcing material or an inorganic filler), polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polyethylene terephthalate, or ABS resin is desirable. However, the constituent material of the 2nd insulation part 3 is not limited to these. In addition, the 1st insulating part 2 and the 2nd insulating part 3 may be comprised with the same material.

  As shown in FIG. 6, the winding 4 is wound around the teeth 12 of the stator core 10 via the first insulating portion 2 and the second insulating portion 3. Specifically, the winding 4 is configured by winding 80 turns of, for example, a magnet wire having a diameter of 1.0 mm around each tooth 12. By arranging the windings 4 in the slots 13 at a high density, copper loss is reduced and the efficiency of the motor is improved.

  Here, the winding 4 is wound by concentrated winding and is connected by Y connection. However, the winding 4 may be wound by distributed winding or may be connected by Δ connection. The number of turns and the diameter of the winding 4 are determined according to required characteristics (rotation speed, torque, etc.), applied voltage, and cross-sectional area of the slot 13.

  FIG. 7 is a perspective view showing an example of the external shape of the first insulating portion 2. As described above, the first insulating portion 2 includes the teeth peripheral portion 2a, the outer wall portion 2b, and the inner wall portion 2c. As described above, the teeth surrounding portion 2a is formed so as to surround the teeth 12 from both sides in the circumferential direction and both sides in the axial direction. Winding 4 (FIG. 6) is wound around this tooth peripheral part 2a.

  Both the outer wall portion 2b and the inner wall portion 2c extend outward in the axial direction from the stator core 10, and constitute a wall portion 22 and a wall portion 21, respectively. These wall portions 21 and 22 are portions that guide the winding 4 (FIG. 2) from both sides in the radial direction outside the stator core 10 in the axial direction.

  The first insulating portion 2 has, for example, a structure (divided structure) that is divided into two parts by a dividing surface 23 formed in the central portion in the axial direction in order to facilitate assembly to the stator core 10. However, it is not limited to such a divided structure, and may be an integral structure. The second insulating portion 3 is hidden in FIG. 7 because it is provided inside the first insulating portion 2.

  Next, the configuration and operation of the second insulating unit 3 will be further described. First, the uneven | corrugated | grooved part and lamination | stacking gap | interval of the stator core 10 which generate | occur | produce in the punching process and lamination | stacking process of the electromagnetic steel plate 101 are demonstrated.

  FIG. 8 is a schematic diagram for explaining the punching process of the electromagnetic steel sheet 101. When the stator core 10 is manufactured, the electromagnetic steel plates 101 are punched one by one in the shape of the stator core 10 (that is, the shape having the yoke portion 11 and the teeth 12). The punching is performed using a press device 70 having an upper die 71 (die) and a lower die 72 (punch).

  Hereinafter, for convenience of explanation, the upper die 71 side surface (that is, the upper surface) of the electromagnetic steel sheet 101 is referred to as the front surface 101a, and the lower die 72 side surface (that is, the lower surface) is referred to as the rear surface 101b.

  The electromagnetic steel plate 101 is punched by applying shear deformation between the upper die 71 and the lower die 72 of the press device 70. When the upper mold 71 is lowered with respect to the lower mold 72, the upper mold 71 and the lower mold 72 bite into the electromagnetic steel sheet 101, and a crack C is generated. When the upper mold 71 is further lowered, the electromagnetic steel sheet 101 breaks starting from the crack C.

  FIGS. 9A and 9B are schematic views of the cut surface (punched surface) of the punched electromagnetic steel sheet 101 as viewed from the side and the front, respectively. On the punched surface of the electromagnetic steel sheet 101, a sloping surface A1, a shear surface A2, a fracture surface A3, and a burr A4 are formed in this order from the front surface 101a side to the back surface 101b side.

  The awl A1 is a curved surface in which the surface 101a of the electromagnetic steel plate 101 is deformed by being pushed down by the upper mold 71. The shear surface A2 is a flat surface generated by rubbing against the upper mold 71, and scratches are formed in the shear direction (here, the vertical direction).

  The fracture surface A3 is a surface broken by the crack C and is a surface rougher than the shear surface A2. The burr A4 (burr) is a protrusion formed by the electromagnetic steel plate 101 being pushed down by the upper mold 71, and protrudes downward from the back surface 101b.

  As shown in FIG. 9A, on the punched surface of the electromagnetic steel sheet 101, the shear surface A2 protrudes outward in the surface direction (direction perpendicular to the thickness direction). The drooping face A1, the fracture surface A3 and the burr A4 are retracted inward from the shear plane A2.

  FIG. 10A is a schematic diagram for explaining a method of forming the crimped portion 17 (18) of the electromagnetic steel plate 101. FIG. Before punching out the electromagnetic steel sheet 101 as shown in FIG. 8, an upper die 92 having a punch 93 and a lower die 90 having a die 91 are used to form concave and convex shapes on the front surface 101a and the rear surface 101b of the electromagnetic steel plate 101. Form a shape. Specifically, by pushing a part of the electromagnetic steel sheet 101 into the die 91 by the punch 93, a convex shape is formed on the back surface 101b side (die 91 side) of the electromagnetic steel sheet 101, and on the front surface 101a side (punch 93 side). A concave shape is formed.

  Thereafter, the electromagnetic steel sheet 101 is punched as shown in FIG. 8, and then, as shown in FIG. 10B, a plurality of electromagnetic steel sheets 101 are laminated in the axial direction. At this time, the convex shape of the back surface 101b of the electromagnetic steel sheet 101 is fitted to the concave shape of the surface 101a of the electromagnetic steel sheet 101 overlapping in the axial direction. In this way, the stator core 10 is obtained in which the plurality of electromagnetic steel plates 101 are fixed to each other by the crimping portion 17 (18).

  The caulking portion 17 (18) may have a circular shape when viewed in the axial direction and a rectangular cross-sectional shape as shown in FIG. 10B, for example. As shown, the shape seen in the axial direction may be rectangular and the cross-sectional shape may be V-shaped. The caulking shape shown in FIG. 10B is formed by using a cylindrical punch 93, and the caulking shape shown in FIG. 10C is formed by using a V-shaped punch 93.

  FIG. 11 is an enlarged cross-sectional view of the end surface of the stator core 10 corresponding to the punched surface of the electromagnetic steel sheet 101. The end surface of the stator core 10 corresponding to the punched surface of the electromagnetic steel sheet 101 includes the outer peripheral surface 11a and the inner peripheral surface 11b of the yoke portion 11 shown in FIG. 1, and the side surface 12a, the protruding surface 12c, and the front end surface of the tooth 12. 12d.

  On the end face of the stator core 10, convex portions 103 including a shear surface A <b> 2 and concave portions 104 including a slant A <b> 1, a fracture surface A <b> 3 and a burr A <b> 4 are alternately formed in the axial direction. The convex portion 103 and the concave portion 104 of the stator core 10 are formed on any of the outer peripheral surface 11a and inner peripheral surface 11b of the yoke portion 11 shown in FIG. 1, the side surface 12a of the tooth 12, the protruding surface 12c, and the front end surface 12d. Is also formed.

  Further, when the electromagnetic steel plates 101 are laminated, the burr A4 of a certain electromagnetic steel plate 101 comes into contact with the surface 101a of the lower electromagnetic steel plate 101. Therefore, a minute gap (referred to as a lamination gap) 102 of several μm is formed between the back surface 101b of a certain electromagnetic steel sheet 101 and the surface 101a of the lower electromagnetic steel sheet 101. The position of the stacking gap 102 in the axial direction is the same as the position of the collar A4 in the axial direction, and the stacking gap 102 communicates with the recess 104.

  12 is an enlarged cross-sectional view of the outer peripheral surface 11a of the yoke portion 11, and corresponds to a cross-sectional view in the direction of the arrow in the line segment 12-12 shown in FIG. The outer peripheral surface 11 a of the yoke portion 11 is fitted to the inner peripheral surface of the frame 7. On the other hand, a flow path for lubricating oil and refrigerant is formed between the frame 7 and the notch 19.

  The laminated gap 102 of the stator core 10 communicates with the recess 104 as described above. Therefore, the lubricating oil and refrigerant flowing between the frame 7 and the notch 19 may enter the inside of the stacking gap 102 through the recess 104 as indicated by arrows in FIG.

  Since the winding 4 is not wound around the yoke portion 11, even if lubricating oil and refrigerant enter the laminated gap 102 from the outer peripheral surface 11 a side (or the notch 19 side) of the yoke portion 11, the influence on the characteristics of the electric motor 100 is not affected. Absent. However, since the winding 4 is wound around the teeth 12, if lubricating oil and refrigerant enter the laminated gap 102 of the teeth 12, a leakage current increases, which may cause a reduction in motor efficiency.

  13 is an enlarged cross-sectional view of the side surface 12a of the tooth 12, the first insulating portion 2 and the second insulating portion 3, and is a cross-sectional view in the direction of the arrow in the line segment 13-13 shown in FIG. It corresponds to. As described above, the first insulating portion 2 and the second insulating portion 3 are provided on the side surface 12 a (the surface on the slot 13 side) of the tooth 12.

  The second insulating portion 3 is formed so as to cover the convex portion 103 on the side surface 12a of the tooth 12 and close the concave portion 104 (that is, the slot 13 side of the stacking gap 102). Note that the second insulating portion 3 only needs to block the concave portion 104, and does not necessarily need to cover the convex portion 103.

  As described above, lubricating oil and refrigerant flow inside the slot 13 (FIG. 6) of the stator core 10. By closing the concave portion 104 on the side surface 12 a of the tooth 12 with the second insulating portion 3, it is possible to suppress the intrusion of the lubricating oil and the refrigerant into the stacked gap 102 communicating with the concave portion 104.

  As described above, since the intrusion of the lubricating oil and the refrigerant into the lamination gap 102 of the teeth 12 (that is, the portion where the winding 4 is wound) is suppressed, the leakage current can be reduced, and the motor efficiency resulting from this can be reduced. The decrease can be suppressed.

  Although the thickness (maximum thickness) of the second insulating portion 3 depends on the size of the concave portion 104, the thickness of the electromagnetic steel plate constituting the stator core 10 (thickness of one sheet) is 1/4 to It is desirable to be within a range of 1/2. The maximum thickness of the second insulating portion 3 refers to the distance from the first insulating portion 2 to the return A4.

  13 shows the first insulating portion 2 and the second insulating portion 3 on the side surface 12a of the tooth 12, but as shown in FIG. 5, the protruding surface 12c of the tooth 12 and the inner periphery of the yoke portion 11 are shown. Similarly, the first insulating portion 2 and the second insulating portion 3 are also formed on the surface 11b. That is, the concave portions 104 formed on the protruding surface 12 c of the tooth 12 and the inner peripheral surface 11 b of the yoke portion 11 are also closed by the second insulating portion 3.

  As described above, the first insulating portion 2 and the second insulating portion are formed on the surface of the stator core 10 on the slot 13 side (the side surface 12a and the protruding surface 12c of the tooth 12 and the inner peripheral surface 11b of the yoke portion 11). 3 and the second insulating portion 3 closes the recess 104 (that is, the slot 13 side of the stacking gap 102), so that the penetration of the lubricating oil and the refrigerant into the stacking gap 102 can be suppressed. Thereby, leakage current can be reduced and motor efficiency can be improved.

  Further, by reducing the thickness of the electromagnetic steel sheet 101, the slump A1, the shear plane A2, the fracture surface A3, and the burr A4 (FIGS. 9A and 9B) can be reduced. Thereby, it becomes possible to make thickness of the 2nd insulation part 3 thin, and can suppress the raise in manufacturing cost. The thickness of the electromagnetic steel plate 101 is desirably in the range of 0.2 mm to 0.35 mm.

<Stator manufacturing process>
Next, the manufacturing process of the stator 1 will be described. FIG. 14 is a flowchart for explaining a manufacturing process of the stator 1. In addition, as shown in FIG. 9 (A), an uneven shape for caulking is formed in advance on the front surface 101a and the back surface 101b of the electromagnetic steel sheet 101.

  First, the electromagnetic steel plates 101 are punched one by one in the shape of the stator core 10 developed in a strip shape (step S11). More specifically, the electromagnetic steel plate 101 is punched into a shape in which the steel plate portions 10B corresponding to the divided iron cores 10A are connected in a strip shape. FIG. 15 is a view showing the punched electromagnetic steel sheet 101. The adjacent steel plate portions 10B are connected to each other by a connecting portion 15 (for example, a plastically deformable thin portion).

  The electromagnetic steel sheet 101 is punched by a press device 70 having an upper die 71 and a lower die 72 as shown in FIG. On the punched surface of the electromagnetic steel sheet 101, a droop A1, a shear surface A2, a fracture surface A3, and a burr A4 (FIGS. 9A and 9B) are formed.

  Here, although the electromagnetic steel sheet 101 is punched into the shape of the stator core 10 expanded in a strip shape (FIG. 15), when the stator core 10 is not configured to connect a plurality of divided cores 10A, The electromagnetic steel plate 101 may be punched into the shape of the annular stator core 10 (FIG. 3).

  Next, the plurality of punched electromagnetic steel plates 101 are stacked in the axial direction (step S12). At this time, as shown in FIGS. 10B and 10C, the plurality of laminated electromagnetic steel plates 101 are fixed to each other by the crimping portions 17 and 18. Thereby, the stator core 10 developed in a band shape is obtained.

  Next, the second insulating portion 3 is formed on the stator core 10 (step S13). More specifically, the second insulating portion 3 is formed on the surface of the stator core 10 on the slot 13 side (that is, the side surface 12a and the protruding surface 12c of the tooth 12 and the inner peripheral surface 11b of the yoke portion 11). To do.

  For example, the stator core 10 is set in a mold, and the resin constituting the second insulating portion 3 is filled in the mold and cured, so that the second surface is formed on the surface of the stator core 10 on the slot 13 side. The insulating part 3 is integrally formed. Thereby, the recess 104 (FIG. 13) on the surface of the stator core 10 on the slot 13 side is closed by the second insulating portion 3.

  At this time, in the stator core 10, the tip insulating surface 12 d of the teeth 12, the outer peripheral surface 11 a of the yoke portion 11, and the dividing surface 16 are previously covered with a cover so that the second insulating portion 3 is not formed. .

  The formation method of the 2nd insulation part 3 is not restricted to integral molding using a metal mold | die. FIG. 16 is a schematic diagram showing a method for forming the second insulating portion 3 using the spray device 82. As shown in FIG. 16, the spray device 82 sprays the surface on the slot 13 side of the stator core 10 (that is, the side surface 12 a and the protruding surface 12 c of the teeth 12 and the inner peripheral surface 11 b of the yoke portion 11). The second insulating portion 3 may be formed by spraying resin and curing the resin.

  When the spray device 82 is used, among the plurality of divided cores 10A of the stator core 10, the divided core 10A for spraying resin is fixed with a jig, and the divided cores 10A on both sides of the divided core 10A are spread so that the distance between adjacent teeth 12 is widened. Next, the connecting portion 15 is rotated. Thereby, since a wide space is formed around the divided iron core 10A for spraying the resin, spraying can be performed easily.

  After forming the second insulating portion 3 in this way, the first insulating portion 2 is attached to the stator core 10 (step S14). That is, the first insulating part 2 (insulator), which is a pre-molded resin molded body, is attached to each divided core 10 </ b> A constituting the stator core 10. When the 1st insulating part 2 has a division structure (Drawing 7), attachment of the 1st insulating part 2 to stator iron core 10 becomes easy.

  Further, the first insulating part 2 may be formed integrally with the stator core 10 and the second insulating part 3 using a mold. For example, the stator core 10 on which the second insulating portion 3 is formed is set in a mold, and the resin constituting the first insulating portion 2 is filled in the mold and cured, so that the stator core is cured. The first insulating portion 2 can be formed on the surface of the ten slots 13 so as to cover the second insulating portion 3.

  Thereafter, the winding 4 is wound around the stator core 10 (step S15). FIGS. 17A and 17B are schematic views for explaining the winding process. First, as shown in FIG. 17B, among the plurality of divided cores 10A of the stator core 10 developed in a strip shape, the divided core 10A around which the winding 4 is wound is fixed with a jig, and the divided cores on both sides thereof are fixed. 10A is rotated around the connecting portion 15 so that the interval between adjacent teeth 12 is widened.

  In this state, the winding 4 is wound around the teeth 12 of the split iron core 10A fixed at the winding position by using the winding nozzle 81 of the winding device. Winding nozzle 81 rotates around tooth 12 as shown by arrow R2 in FIG. 17B, and winds winding 4 around tooth 12. Since a wide space is formed around the teeth 12, the winding 4 can be easily wound.

  After winding the winding 4 around each tooth 12, as shown in FIG. 17A, the stator core 10 is assembled into an annular shape (step S16). That is, the stator core 10 is bent into an annular shape, and the butted portions (indicated by the symbol W in FIG. 1) of the split cores 10A at both ends of the stator core 10 are butted together and welded.

  Thereby, the stator 1 provided with the stator core 10, the 1st insulating part 2, the 2nd insulating part 3, and the coil | winding 4 is completed. Note that when the electromagnetic steel plate 101 is punched in the above-described step S11, step S16 (annular assembly process) is not necessary. The stator 1 is incorporated inside the frame 7 of the compressor 500 by shrink fitting, press fitting, or welding.

  On the other hand, the rotor core 50 of the rotor 5 is formed by punching electromagnetic steel sheets one by one into the shape of the rotor core 50, laminating them in the axial direction, and fixing them from both sides in the axial direction with fixing members 61 and 62 (FIG. 2). It is obtained by doing. The rotor 5 is obtained by inserting the permanent magnet 53 into the magnet insertion hole 51 of the rotor core 50 and inserting the shaft 55 into the center hole 54. This rotor 5 is inserted inside the stator 1 attached in the frame 7. Thereby, the electric motor 100 shown in FIG. 1 is completed.

  In the compressor 500, the lubricating oil and the refrigerant flow inside the slot 13 of the electric motor 100 and between the notch 19 and the frame 7, but the surface of the stator core 10 on the slot 13 side has a recess 104 (that is, The second insulating portion 3 is formed so as to close the slot 13 side of the stacking gap 102. Therefore, it is possible to suppress the intrusion of the lubricating oil and the refrigerant into the laminated gap 102 in the portion where the winding 4 of the stator core 10 is wound (that is, the tooth 12). Thereby, leakage current can be reduced and motor efficiency can be improved.

  The second insulating portion 3 is most preferably formed on all of the side surface 12a and the projecting surface 12c of the tooth 12 and the inner peripheral surface 11b of the yoke portion 11, but the side surface 12a and the projecting surface 12c of the tooth 12 and the yoke. If it forms in at least one of the inner peripheral surfaces 11b of the part 11, the effect that it becomes difficult for lubricating oil and a refrigerant | coolant to penetrate | invade into the lamination | stacking clearance gap 102 of the teeth 12 is acquired.

  Moreover, although the electromagnetic steel plate was used here as a lamination | stacking element which comprises the stator core 10, it is not limited to an electromagnetic steel plate, For example, ribbons, such as an amorphous alloy, may be sufficient.

<Drive circuit>
Next, a drive circuit 201 as a drive device that drives the electric motor 100 will be described. FIG. 18 is a block diagram showing the drive circuit 201 of the electric motor 100. The drive circuit 201 includes a rectifier circuit 203 that converts an AC voltage supplied from a commercial AC power source 202 into a DC voltage, and an inverter that converts the DC voltage output from the rectifier circuit 203 into an AC voltage and supplies the AC voltage to the motor 100. A circuit 204 (inverter) and a main element driving circuit 205 for driving the inverter main circuit 204 are included.

  The drive circuit 201 also includes a DC voltage detection unit 208 that detects the DC voltage output from the rectifier circuit 203, and a rotor position detection unit that detects the terminal voltage of the electric motor 100 and detects the position of the rotor of the electric motor 100. 210, an output voltage calculation unit 211 that calculates the optimum output voltage of the inverter main circuit 204, and a PWM that outputs a PWM (Pulse Width Modulation) signal to the main element drive circuit 205 based on the calculation result of the output voltage calculation unit 211 A signal generation unit 212.

  The rectifier circuit 203 includes a chopper circuit that boosts the voltage supplied from the commercial AC power supply 202, a smoothing capacitor that smoothes the rectified DC voltage, and the like.

  The inverter main circuit 204 is a three-phase bridge inverter circuit. The switching unit of the inverter main circuit 204 includes six IGBTs (insulated gate bipolar transistors) 206a to 206f as inverter main elements and six SiC-SBDs (silicon carbide (SiC) as fast recovery diodes (FRD)). Schottky barrier diodes) 207a to 207f. SiC-SBDs 207a to 207f, which are FRDs, are reverse current prevention means for suppressing back electromotive force generated when the IGBTs 206a to 206f turn from ON to OFF.

  Here, the IGBTs 206a to 206f and the SiC-SBDs 207a to 207f are configured by IC modules in which each chip is mounted on the same lead frame and molded by epoxy resin and packaged. The IGBTs 206a to 206f may be formed of IGBTs using SiC or GaN instead of IGBTs using silicon (Si-IGBT). Further, other switching elements such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) using Si, SiC or GaN instead of the IGBT may be used.

  Between the rectifier circuit 203 and the inverter main circuit 204, two voltage dividing resistors 208a and 208b connected in series are provided. The DC voltage detection unit 208 samples and holds an electric signal obtained by reducing the high DC voltage by a voltage dividing circuit using these voltage dividing resistors 208a and 208b.

  The AC power supplied from the inverter main circuit 204 is supplied to the winding 4 of the electric motor 100 through the glass terminal 511 (FIG. 22) of the compressor 500, and the rotor 5 is rotated by the rotating magnetic field.

  The rotor position detector 210 detects the position information of the rotor 5 and outputs it to the output voltage calculator 211. The output voltage calculation unit 211 is an optimum inverter main unit to be supplied to the electric motor 100 based on the command of the target rotational speed N given from the outside of the drive circuit 201 or information on the operating conditions of the device and the position information of the rotor 5. The output voltage of the circuit 204 is calculated. The output voltage calculation unit 211 outputs the calculated output voltage to the PWM signal generation unit 212.

  The PWM signal generation unit 212 outputs a PWM signal having the output voltage given from the output voltage calculation unit 211 to the main element drive circuit 205 that drives the IGBTs 206a to 206f of the inverter main circuit 204. The IGBTs 206 a to 206 f of the inverter main circuit 204 are switched by the main element drive circuit 205.

  SiC used for the SiC-SBDs 207a to 207f is one of wide band gap semiconductors. A wide band gap semiconductor is a generic term for semiconductors having a larger band gap than Si, and includes gallium nitride (GaN), diamond, and the like in addition to SiC. Wide band gap semiconductors, especially SiC, have higher heat resistance, dielectric breakdown strength, and thermal conductivity than Si. Here, SiC is used for the FRD of the inverter circuit, but other wide band gap semiconductors may be used instead of SiC.

  The electric motor 100 performs variable speed driving by PWM control by the inverter main circuit 204 of the driving circuit 201, thereby performing high-efficiency operation according to the requested load condition. The switching frequency (carrier frequency) of the inverter main circuit 204 varies depending on the switching element used in the main element driving circuit 205. For example, when GaN is used for the main element drive circuit 205, a waveform is generated at about 100 kHz, and the drive voltage includes a high frequency due to switching higher than the operation frequency.

  When a high-frequency potential difference is generated between the stator core 10 and the winding 4 during high-frequency operation by PWM control, leakage current tends to flow due to floating capacitance. The principle of this leakage current is the same as that of the capacitor, and the relationship of i = 2πfCV is established among the leakage current i, the frequency f, the capacitance C, and the voltage V. That is, the leakage current i is proportional to the product of the frequency f, the capacitance C, and the voltage V.

  Further, between the capacitance C, the surface area S of the winding 4 near the surface of the stator core 10 on the slot 13 side, and the shortest distance d between the stator core 10 and the winding 4, C = The relationship of εS / d is established. Here, ε is a dielectric constant and varies depending on the substance. Usually, a relative dielectric constant εr (= ε / ε0), which is a ratio with a vacuum dielectric constant ε0, is used.

  Between the stator core 10 and the winding 4, the first insulating part 2, the second insulating part 3, and lubricating oil and refrigerant exist. The relative dielectric constant of the lubricating oil (refrigerating machine oil) used in the compressor 500 is 4-7. The relative dielectric constant of the refrigerant used in the compressor 500 is 7-12. The relative dielectric constant of the material (resin) constituting the first insulating portion 2 and the second insulating portion 3 is 3 to 5. That is, the relative dielectric constant increases in the order of resin, lubricant, and refrigerant.

  Therefore, by providing the second insulating portion 3 having a relative dielectric constant smaller than that of the lubricating oil and the refrigerant on the surface of the stator core 10 on the slot 13 side, the capacitance C in the above relational expression i = 2πfCV is reduced. can do. That is, the leakage current i caused by the potential difference between the stator core 10 and the winding 4 during high frequency operation can be suppressed.

<Effect of Embodiment>
As described above, according to the first embodiment of the present invention, the first insulating portion 2 is provided in the slot 13 of the stator core 10, and between the stator core 10 and the first insulating portion 2. The second insulating part 3 is provided on the side of the slot 13 of the laminated gap 102. Therefore, the penetration of the lubricating oil and the refrigerant flowing through the slot 13 into the stacked gap 102 can be suppressed. As a result, leakage current due to the intrusion of the lubricating oil and the refrigerant into the laminated gap 102 of the stator core 10 can be reduced, and the motor efficiency can be improved.

  Further, by reducing the intrusion of the lubricating oil and the refrigerant into the stacking gap 102 of the stator core 10, it is possible to suppress the fluctuation of the leakage current due to the variation in the degree of the intrusion of the lubricating oil and the refrigerant. Reliability can be improved.

  Further, by reducing the leakage current as described above, the carrier frequency of PWM control of the inverter can be increased using, for example, SiC or GaN. By increasing the carrier frequency, the control resolution can be improved and the electric motor 100 can be driven at high speed. Thereby, the rotation speed of the compressor 500 can be increased and an output can be improved. Moreover, the air conditioning apparatus 600 (FIG. 23) using the compressor 500 can improve the air conditioning capability, and can improve comfort.

  In addition, a recess 104 communicating with the stacking gap 102 is formed on the surface of the stator core 10 on the slot 13 side, and the second insulating portion 3 closes the recess 104. Therefore, lubrication from the recess 104 to the stacking gap 102 is achieved. The penetration of oil and refrigerant can be suppressed, and the leakage current can be effectively suppressed.

  Further, since the second insulating portion 3 is made of a material having a relative dielectric constant smaller than that of the lubricating oil and the refrigerant, leakage that occurs due to a potential difference between the stator core 10 and the winding 4 when the electric motor 100 is operated at a high frequency. The current can be reduced.

  Moreover, since the 2nd insulation part 3 is formed in the side surface 12a of the teeth 12, it suppresses the penetration | invasion of lubricating oil and a refrigerant | coolant to the lamination | stacking clearance gap 102 of the teeth 12 in which the coil | winding 4 is wound, and suppresses a leakage current. Can enhance the effect.

  Further, since the second insulating portion 3 is also formed on the inner peripheral surface 11 b of the yoke portion 11, it is possible to suppress the intrusion of the lubricating oil and the refrigerant from the yoke portion 11 to the stacked gap 102 of the teeth 12. .

  Moreover, since the 2nd insulation part 3 is also formed in the protrusion surface 12c of the protrusion part 121 of the front-end | tip of the teeth 12, it is effective for the penetration | invasion of lubricating oil and a refrigerant | coolant from the protrusion part 121 to the lamination | stacking clearance gap 102 of the teeth 12. FIG. Can be suppressed.

  Further, since the thickness of the second insulating portion 3 is within a range of ¼ to ½ of the thickness of the electromagnetic steel plate 101 constituting the stator core 10, the recess 104 (that is, the slot of the stacking gap 102). 13 side) can be effectively blocked, and the intrusion of lubricating oil and refrigerant can be suppressed.

  Further, since the thickness of the electromagnetic steel sheet 101 constituting the stator core 10 is within the range of 0.2 to 0.35 mm, the wholly generated A1 on the punched surface of the electromagnetic steel sheet 101, the shear surface A2, the fracture surface A3, and The return A4 can be reduced. Thereby, the thickness of the 2nd insulation part 3 can be made thin and manufacturing cost can be reduced.

  In the example shown in FIG. 13, the second insulating portion 3 is formed so as to close the concave portion 104 of the stator core 10, and does not enter the laminated gap 102. However, as shown in an example in FIG. 19, the second insulating portion 3 may enter the stacked gap 102 from the recess 104. Since the second insulating portion 3 has an insulating property, even if the second insulating portion 3 enters the laminated gap 102, it does not cause a leakage current.

Embodiment 2. FIG.
FIG. 20 is an enlarged cross-sectional view showing the surface on the slot 13 side (here, the side surface 12a of the tooth 12) and the insulating portion 30 of the stator core 10 in the electric motor according to the second embodiment. This corresponds to a cross-sectional view in the direction of the arrow in minutes 13-13.

  In the second embodiment, the first insulating portion 2 and the second insulating portion 3 are integrated to form the insulating portion 30. The insulating portion 30 is formed so as to close the concave portion 104 on the surface of the stator core 10 on the slot 13 side, and suppresses the intrusion of the lubricating oil and the refrigerant into the laminated gap 102. The insulating part 30 may enter the laminated gap 102 from the recess 104 (see FIG. 19). A winding 4 (see FIG. 1) is wound around the insulating portion 30.

  The insulating part 30 can be made of the same material as that of the first insulating part 2 and the second insulating part 3 described in the first embodiment. The insulating part 30 is preferably made of a material having a relative dielectric constant smaller than that of the lubricating oil and the refrigerant. The insulating part 30 is formed, for example, by setting the stator core 10 in a mold, filling the mold with resin, and curing the resin. Further, as shown in FIG. 16, a spray-like resin may be sprayed on the stator core 10 to be cured.

  Although FIG. 19 shows the insulating portion 30 formed on the side surface 12a of the tooth 12, the same insulating portion 30 is also applied to the protruding surface 12c of the tooth 12 and the inner peripheral surface 11b of the yoke portion 11 (see FIG. 5). Is formed.

  The electric motor according to the second embodiment is configured in the same manner as the electric motor 100 according to the first embodiment except that the first insulating part 2 and the second insulating part 3 are replaced with an insulating part 30. The stator manufacturing process according to the second embodiment is the same as the stator 1 according to the first embodiment except that Step S13 and Step S14 are performed simultaneously in a single process (that is, the process of forming the insulating portion 30). This is the same as the manufacturing process (FIG. 14).

  In the second embodiment, as in the first embodiment, it is possible to reduce the intrusion of the lubricating oil and the refrigerant into the laminated gap 102 in the portion (that is, the tooth 12) where the winding 4 of the stator core 10 is wound. Thereby, leakage current can be suppressed and motor efficiency can be improved.

  In the second embodiment, since the single insulating portion 30 is used instead of the first insulating portion 2 and the second insulating portion 3 of the first embodiment, the manufacturing process of the stator 1 is simplified. be able to.

Embodiment 3 FIG.
FIG. 21 is a cross-sectional view showing electric motor 300 of the third embodiment. The electric motor 300 of the third embodiment is different from the electric motor 100 of the first embodiment in that the rotor 305 has an outer rotor configuration in which the rotor 305 is disposed outside the stator 301. The electric motor 300 is used for the compressor 500 (FIG. 22), for example.

  The stator 301 includes, for example, a stator core 310 in which electromagnetic steel plates (lamination elements) having a thickness of 0.2 to 0.5 mm (preferably 0.2 to 0.35 mm) are laminated in the direction of the axis C1, and the stator. It has the coil | winding 4 (refer FIG. 1) wound around the iron core 310. FIG. Note that the winding 4 is omitted in FIG.

  The stator core 310 includes an annular yoke portion 311 centering on the axis C1 and a plurality of teeth 312 extending from the yoke portion 311 radially outward (opposite to the axis C1). The number of teeth 312 is four here, but is not limited to four. Between the teeth 312 adjacent in the circumferential direction, a slot 313 which is a space for accommodating the winding 4 is formed. In the slot 313, the lubricating oil and refrigerant of the compressor 500 (FIG. 22) flow.

  Although omitted in FIG. 21, the yoke portion 311 and the tooth 312 are formed with caulking portions for fixing a plurality of electromagnetic steel plates to each other.

  The teeth 312 have side surfaces 312a that are both end surfaces in the circumferential direction. Further, the tooth 312 has a tooth tip 320 at the radially outer end (ie, tip). The teeth tip portion 320 has protruding portions 321 that protrude on both sides in the circumferential direction with respect to the side surface 312 a of the tooth 312. A protruding surface 312c that faces the yoke portion 311 is formed on the radially inner side of the protruding portion 321. The side surface 312 a and the protruding surface 312 c of the tooth 312 face the slot 313.

  The yoke portion 311 has an annular inner peripheral surface 311a and an outer peripheral surface 311b centered on the axis. A shaft 355 connected to the rotor 305 is disposed inside the inner peripheral surface 311a. A gap is provided between the inner peripheral surface 311a of the yoke portion 311 and the shaft 355 so as not to contact each other. The outer peripheral surface 311 b of the yoke portion 311 faces the slot 313.

  That is, in the third embodiment, the surface on the slot 313 side of the stator core 310 is the side surface 312a and the protruding surface 312c of the tooth 312 and the outer peripheral surface 311b of the yoke portion 311.

  A second insulating portion 303 is formed on the surface of the stator core 310 on the slot 313 side (the side surface 312a and the protruding surface 312c of the tooth 312 and the outer peripheral surface 311b of the yoke portion 311). Further, a first insulating portion 302 is provided so as to cover the second insulating portion 303. The constituent materials and thicknesses of the first insulating portion 302 and the second insulating portion 303 are the same as those of the first insulating portion 2 and the second insulating portion 3 of the first embodiment, respectively.

  The second insulating portion 303 can be formed integrally with the stator core 310 using a mold, like the second insulating portion 3 of the first embodiment. Further, resin may be sprayed onto the stator core 310 by a spray device.

  As with the first insulating portion 2 of the first embodiment, the first insulating portion 302 is formed by assembling a pre-molded resin molded body to the stator core 310, or using a mold and the stator core 310 and the first insulating portion 302. 2 insulating portions 3 can be formed integrally.

  The first insulating portion 302 and the second insulating portion 303 can be made of the same material as that of the first insulating portion 2 and the second insulating portion 3 described in the first embodiment. The first insulating portion 302 and the second insulating portion 303 are preferably made of a material having a relative dielectric constant smaller than that of the lubricating oil and the refrigerant.

  Convex portions and concave portions similar to the convex portions 103 and concave portions 104 shown in FIG. 13 are formed on the end surface of the stator core 310. In addition, a laminating gap similar to the laminating gap 102 shown in FIG. 13 is formed in the gap between the electromagnetic steel sheets constituting the stator core 310.

  Second insulating portion 303 of the second embodiment closes the recesses on the surface of stator core 310 on the slot 313 side (side surface 312a and protruding surface 312c of teeth 312 and outer peripheral surface 311b of yoke portion 311). Yes.

  Therefore, it is possible to suppress the intrusion of the lubricating oil and the refrigerant into the lamination gap of the portion around which the winding 4 of the stator core 310 is wound (that is, the tooth 312), and to reduce the leakage current. The thickness of the second insulating portion 303 is preferably within a range of ¼ to ½ of the thickness of the electromagnetic steel plate constituting the stator core 310.

  If the second insulating portion 303 is formed on at least one of the side surface 312 a and the protruding surface 312 c of the tooth 312 and the outer peripheral surface 311 b of the yoke portion 311, the lubricating oil and the refrigerant are provided in the stacking gap of the tooth 312. Can be prevented from entering.

  The rotor 305 includes an annular rotor core 350 centered on the axis C <b> 1 and a plurality of permanent magnets 351 disposed along the inner periphery of the rotor core 350. The number of permanent magnets 351 is six here, but is not limited to six. The rotor 305 is fixed to the shaft 355 via a hub (not shown), and the axis C1 is the rotation center of the shaft 355.

  The electric motor 300 can be driven by the drive circuit 201 (FIG. 18) described in the first embodiment, for example.

  The manufacturing method of the stator 301 is as follows. That is, the electromagnetic steel sheets on which the concavo-convex shape for caulking is formed in advance are punched one by one in the shape of the stator core 310. Subsequently, a plurality of electromagnetic steel plates are stacked and fixed to each other by caulking portions to obtain a stator core 310. Next, the second insulating portion 303 is formed on the surface of the stator core 310 on the slot 313 side. Further, the first insulating portion 302 is assembled or integrally formed so as to cover the second insulating portion 303. Thereafter, the winding 4 is wound around the teeth 312 of the stator core 310 via the first insulating portion 302. Thereby, the stator 301 is obtained.

  In the third embodiment, in the outer rotor type electric motor 300, the first insulating portion 302 is provided inside the slot 313 of the stator core 310, and the first insulating portion 302 is interposed between the stator core 310 and the first insulating portion 302. Two insulating portions 303 are provided, and the second insulating portion 303 closes the slot 313 side of the stacking gap. Therefore, the penetration of the lubricating oil and refrigerant flowing through the slot 313 into the stacking gap can be reduced. Thereby, leakage current can be reduced and motor efficiency can be improved.

  Note that as described in Embodiment Mode 2, the first insulating portion 302 and the second insulating portion 303 may be integrally formed. Further, as shown in FIG. 19, the second insulating portion 303 may enter the stacking gap of the stator core 310.

<Compressor>
Next, a compressor (rotary compressor) 500 to which the electric motor 100 of each embodiment can be applied will be described. FIG. 22 is a cross-sectional view showing a configuration of the compressor 500. The compressor 500 includes an airtight container 507, a compression element 501 disposed in the airtight container 507, and an electric motor 100 that drives the compression element 501. The electric motor 100 is the electric motor 100 (FIG. 1) described in the first embodiment, but may be the electric motor described in the second or third embodiment.

  The compression element 501 includes a cylinder 502 having a cylinder chamber 503, a shaft 55 rotated by the electric motor 100, a rolling piston 504 fixed to the shaft 55, and a vane (not shown) that divides the cylinder chamber 503 into a suction side and a compression side. And an upper frame 505 and a lower frame 506 that insert the shaft 55 and close the axial end surface of the cylinder chamber 503. An upper discharge muffler 508 and a lower discharge muffler 509 are mounted on the upper frame 505 and the lower frame 506, respectively.

  The sealed container 507 is a cylindrical container formed by drawing a steel plate having a thickness of 3 mm, for example. Refrigerating machine oil (not shown) as a lubricant that lubricates each sliding portion of the compression element 501 is stored at the bottom of the sealed container 507. The shaft 55 is rotatably held by an upper frame 505 and a lower frame 506 as bearing portions.

  The cylinder 502 includes a cylinder chamber 503 inside, and the rolling piston 504 rotates eccentrically within the cylinder chamber 503. The shaft 55 has an eccentric shaft portion, and a rolling piston 504 is fitted to the eccentric shaft portion.

  The sealed container 507 has a cylindrical frame 7. The stator 1 of the electric motor 100 is incorporated inside the frame 7 by a method such as shrink fitting, press fitting, or welding. Electric power is supplied to the winding 4 of the stator 1 from a glass terminal 511 fixed to the hermetic container 507. The shaft 55 is fixed to a center hole 54 formed at the center of the rotor core 50 (FIG. 1) of the rotor 5.

  An accumulator 510 that stores refrigerant gas is attached to the outside of the sealed container 507. A suction pipe 513 is fixed to the sealed container 507, and refrigerant gas is supplied from the accumulator 510 to the cylinder 502 via the suction pipe 513. In addition, a discharge pipe 512 for discharging the refrigerant to the outside is provided at the upper part of the sealed container 507.

  For example, R410A, R407C, or R22 can be used as the refrigerant. Moreover, it is desirable to use a low GWP (global warming potential) refrigerant from the viewpoint of preventing global warming.

  The operation of the compressor 500 is as follows. The refrigerant gas supplied from the accumulator 510 is supplied into the cylinder chamber 503 of the cylinder 502 through the suction pipe 513. When the electric motor 100 is driven by energization of the inverter and the rotor 5 rotates, the shaft 55 rotates together with the rotor 5. Then, the rolling piston 504 fitted to the shaft 55 rotates eccentrically in the cylinder chamber 503, and the refrigerant is compressed in the cylinder chamber 503. The refrigerant compressed in the cylinder chamber 503 passes through the discharge mufflers 508 and 509, and further passes between the slot 13 (FIG. 6) and the notch 19 of the stator core 10 and the frame 7, and rises in the sealed container 507. To do. The refrigerant rising in the sealed container 507 is discharged from the discharge pipe 512 and supplied to the high-pressure side of the refrigeration cycle.

  The refrigerant compressed in the cylinder chamber 503 contains refrigeration oil. However, when the refrigerant passes through the slot 13 (FIG. 6) of the stator core 10, the separation of the refrigerant and the refrigeration oil is promoted. Inflow of the refrigerating machine oil into the discharge pipe 512 is prevented.

  The electric motor 100 described in each embodiment can be applied to the electric motor 100 of the compressor 500, and has high electric motor efficiency and high reliability by reducing leakage current. Therefore, the operation efficiency and reliability of the compressor 500 can be improved.

  Further, the electric motor 100 can be driven at a high carrier frequency by reducing the leakage current, and can be driven at a high speed. Therefore, the rotation speed of the compressor 500 can be increased and the output can be improved.

  In addition, the electric motor demonstrated by each embodiment can be utilized not only for a rotary compressor but for another kind of compressor.

  Moreover, the electric motor demonstrated in each embodiment can be used for apparatuses other than a compressor. Even when the electric motor is used in an apparatus other than the compressor, for example, lubricating oil (not limited to refrigerating machine oil) can be prevented from entering the gap between the electromagnetic steel sheets constituting the stator core.

<Air conditioning device>
Next, the air conditioning apparatus 600 (refrigeration air conditioner) provided with the compressor 500 mentioned above is demonstrated. FIG. 23 is a diagram illustrating a configuration of the air conditioning apparatus 600. An air conditioner 600 shown in FIG. 23 includes a compressor (rotary compressor) 500, a four-way valve 601, a condenser 602, a decompression device (expander) 603, an evaporator 604, a refrigerant pipe 605, And a control unit 606. The compressor 500, the condenser 602, the decompression device 603, and the evaporator 604 are connected by a refrigerant pipe 605 to constitute a refrigeration cycle.

  The operation of the air conditioner 600 is as follows. The compressor 500 compresses the sucked refrigerant and sends it out as a high-temperature and high-pressure gas refrigerant. The four-way valve 601 switches the flow direction of the refrigerant. In the state shown in FIG. 23, the refrigerant sent out from the compressor 500 flows to the condenser 602. The condenser 602 exchanges heat between the refrigerant sent from the compressor 500 and air (for example, outdoor air), condenses and liquefies the refrigerant, and sends it out. The decompression device 603 expands the liquid refrigerant sent out from the condenser 602 and sends it out as a low-temperature and low-pressure liquid refrigerant.

  The evaporator 604 exchanges heat between the low-temperature and low-pressure liquid refrigerant sent out from the decompression device 603 and air (for example, indoor air), causes the refrigerant to take away the heat of the air, and evaporates (vaporizes) the gas refrigerant. Send out as. The air from which heat has been removed by the evaporator 604 is supplied to a target space (for example, a room) by a blower (not shown). The operations of the four-way valve 601 and the compressor 500 are controlled by the control unit 606.

  The electric motor described in each embodiment can be applied to the compressor 500 of the air conditioner 600, and has high operating efficiency and high reliability due to reduction of leakage current. Therefore, the operation efficiency and reliability of the air conditioner 600 can be improved. Moreover, since the compressor 500 can respond to high rotation speed and high output, it can improve the cooling capability of the air conditioning apparatus 600 (FIG. 23), and can improve comfort.

  In addition, components other than the compressor 500 in the air conditioning apparatus 600 are not limited to the above-described configuration example.

  The preferred embodiments of the present invention have been specifically described above. However, the present invention is not limited to the above-described embodiments, and various improvements or modifications are made without departing from the scope of the present invention. be able to.

  DESCRIPTION OF SYMBOLS 1 Stator, 2 1st insulation part (insulator), 2a Teeth surrounding part, 2b Outer wall part, 2c Inner wall part, 3 2nd insulation part (blocking part), 3a Teeth side part, 3b York inner surface part, 3c Teeth protruding surface part, 4 windings, 5 rotors, 7 frames, 10 stator cores, 10A split iron cores, 10B steel plate parts, 10a outer peripheral surface, 11 yoke parts, 11a outer peripheral surface, 11b inner peripheral surface, 11c hole, 12 Teeth, 12a side surface, 12b end surface, 12c projecting surface, 12d tip surface, 13 slot, 15 connecting portion, 16 dividing surface, 17, 18 crimping portion, 19 notch, 21, 22 wall portion, 23 dividing surface, 30 insulating portion 50 rotor cores, 51 magnet insertion holes, 52 flux barriers, 53 permanent magnets, 5 4 Center hole, 55 shaft, 100 electric motor, 101 electromagnetic steel plate, 101a surface, 101b back surface, 102 stacking gap (gap), 103 convex portion, 104 concave portion, 120 teeth tip portion, 121 protruding portion, 201 drive circuit, 202 commercial AC Power source, 203 rectifier circuit, 204 inverter main circuit (inverter), 205 main element drive circuit, 212 PWM signal generation unit, 300 motor, 301 stator, 302 first insulation unit, 303 second insulation unit, 305 rotor 310 stator core, 311 yoke portion, 311b outer peripheral surface, 312 teeth, 312a side surface, 312c projecting surface, 313 slot, 320 teeth tip, 321 projecting portion 321, 350 rotor core, 351 permanent magnet, 500 Compressor, 501 compression element, 507 sealed container, 600 air conditioner, 601 four-way valve, 602 condenser, 603 decompressor, 604 evaporator, 605 refrigerant pipe, A1 droop, A2 shear plane, A3 fracture surface, A4 burr.

The stator according to the present invention includes a yoke portion extending in the circumferential direction around the axis, a plurality of teeth extending in a direction from the yoke portion toward the axis or in a direction away from the axis, and a circumference of the plurality of teeth. A stator core having a slot formed between two teeth adjacent to each other in a direction, wherein a plurality of laminated elements are laminated in the direction of the axis, and two of the laminated elements adjacent to each other in the axis direction A stator core having a gap between the laminated elements, an insulating portion provided in the slot, closing the slot side of the gap and integrally formed of the same material, and a winding wound around the insulating portion .

Claims (19)

A yoke portion extending in a circumferential direction centering on the axis, a plurality of teeth extending in a direction from the yoke portion toward the axis or in a direction away from the axis, and among the plurality of teeth, adjacent to the circumferential direction A stator core having a slot formed between two matching teeth, wherein a plurality of laminated elements are laminated in the direction of the axis, and two adjacent ones of the plurality of laminated elements in the direction of the axis. A stator core having a gap between the laminated elements;
A first insulating portion provided in the slot;
A stator comprising: a second insulating portion provided between the stator iron core and the first insulating portion and closing the slot side of the gap. The stator according to claim 1, wherein the first insulating portion and the second insulating portion are made of the same material. The stator according to claim 1 or 2, wherein the first insulating portion and the second insulating portion are integrally formed. The stator according to any one of claims 1 to 3, wherein the second insulating portion is made of a material having a relative dielectric constant smaller than at least one of lubricating oil and refrigerant. On the surface of the stator core on the slot side, a recess communicating with the gap is formed,
The stator according to any one of claims 1 to 4, wherein the second insulating portion closes the concave portion. The stator according to any one of claims 1 to 5, wherein the second insulating portion penetrates into the gap. The stator according to any one of claims 1 to 6, wherein a thickness of the second insulating portion is ¼ or more and ½ or less of a thickness of one of the laminated elements. The stator according to any one of claims 1 to 7, wherein the second insulating portion is formed on a surface of each of the plurality of teeth on the slot side. The stator according to any one of claims 1 to 8, wherein the second insulating portion is formed on a surface of the yoke portion on the slot side. At the tip of each of the plurality of teeth, has a protruding portion protruding in the circumferential direction,
The stator according to any one of claims 1 to 9, wherein the second insulating portion is formed on a surface of the protruding portion on the slot side. The stator according to any one of claims 1 to 10, wherein a thickness of each of the plurality of laminated elements of the stator core is 0.2 mm or more and 0.35 mm or less. The stator according to any one of claims 1 to 11,
And a rotor provided inside or outside the stator in a radial direction centered on the axis. A drive device for driving the electric motor according to claim 12,
A rectifier circuit that is supplied with a voltage from a power source and outputs a DC voltage;
An inverter that converts the DC voltage to an AC voltage and outputs the AC voltage to the motor;
At least one of the rectifier circuit and the inverter has a wide band gap semiconductor as a switching element. The driving device according to claim 13, wherein the rectifier circuit has a boosting function of boosting a voltage supplied from the power source. An electric motor and a compression element driven by the electric motor,
The said electric motor is a compressor provided with the stator of any one of Claim 1-11, and the rotor provided in the inner side or the outer side of the said stator in the radial direction centering on the said axis. Equipped with a compressor, condenser, decompressor and evaporator,
The compressor includes an electric motor and a compression element driven by the electric motor,
The said electric motor is provided with the stator of any one of Claim 1-11, and the rotor provided in the inner side or the outer side of the said stator in the radial direction centering on the said axis. . A yoke portion extending in a circumferential direction centering on the axis, a plurality of teeth extending in a direction from the yoke portion toward the axis or in a direction away from the axis, and among the plurality of teeth, adjacent to the circumferential direction A slot formed between two matching teeth, and a plurality of laminated elements are laminated in the direction of the axis, and the two laminated elements adjacent to each other in the direction of the axis are stacked. Preparing a stator core having a gap;
Providing a second insulating part on the slot side surface of the stator core so as to close the slot side of the gap;
Providing the first insulating portion so as to cover the second insulating portion. The method for manufacturing a stator according to claim 17, wherein the step of providing the second insulating portion includes a step of integrally forming a resin constituting the second insulating portion on the stator core. The first insulating part and the second insulating part are integrally formed,
The method of manufacturing a stator according to claim 17 or 18, wherein the step of providing the second insulating portion and the step of providing the first insulating portion are performed in a single step.

Images